This is my attic listening space. In an attempt to follow Linkwitz's recommended speaker placement, I have arrived at a 5' equilateral triangle with 3' to room boundaries. I use a minimal amount of digital speaker/room correction (DRC 3.1) based on an impulse response I recorded at the sweet spot with a calibrated measurement mic. I play flac files in foobar (with convolver and upsampler to 176.4k) to an m2tech hiFace Evo using optical output to Altmann converter and amp. Oh, and of course my beloved RL 1.5's. It's a small space but it doesn't sound that way with your eyes closed. I couldn't be happier.

The battery is an Optima red top which is the power supply recommended by Charles Altmann. Pure power with no need for conversion/regulation/filtration/rectification etc.... The disconnected cable in the photo is the positive lead from the charger (which is hidden under the cabinet). The negative lead stays connected. When I power down, I simply swap that cable with dac/amp positive lead and the battery gets charged/conditioned.

Big update - Decided to renovate the space for a couple of reasons and seized the oppurtunity to improve the acoustics. The new space features solid pine/cedar ceiling and walls. The ceiling is now cathedral. The floor is 3/4" elm which was installed on top of the old floor (3/4" oak which had been painted to look like tile) and runs perpendicular to it making for a very stiff 1.5" "ply". The sound is a touch more dry/warm and much more consistant throughout the room. Loving it so far....

When I bought the amp it was half that price but that was over 6 years ago. I think the Decware prices have risen proportionally in that time period. It does seem pricey though so long as you're looking at it ;)

I think I remember someone in the old forum had taken an early Zen amp and made it battery powered. I'm curious how much of an improvement that was, and your system just seems to be the solid state epitome of simplicity.